All the time spent gathering, then making sure all the right res are all in the right spot then waiting an absurdly high wait time for a single item.  

Then you get to send the item back to the appropriate city, and finally equip.  Then you have to figure out the terrain, and type of enemy your likely to be fighting.  Then go through your list of equipment to find out whats best, and instead of just being a simple +x%, or a simple +x% in biome, ect.  All equipment have like 5 modifiers.  So you have to do a ton of mental math to figure out which equipment is most likely the best.  

Finally you get to equip and engage.  And you get maybe +6% woot!!!!, also if you did some of that mental math wrong or end up fighting a different unit that you thought you would well it turns out its gonna be -18%

So yea 99% of the equipment can be ignored.  Honestly I love the idea just not the implementation.  They have already increased build times for equipment once, I wouldn't mind seeing build times be closer to gather times, in its current state you need like 9 crafting cites for every 1 gatherer.  

hen change the stats to be more useful.  Think +100%, and instead of all the +x%, -y%, -z%.  Just be simple such as 'better spear' +100%.  There are weapons out there that have 15 modifiers over half of them negative.  Or weapons with 2 positive and 8 negative.  And there aren't just a few of them, there are tons of these weapons where you have to spend 5mins just to figure out if the equipment will help or hurt your army.  Once you figure that out you get to try and decide if spending the last 2 hrs going through all that stuff I just listed was worth it to get +2% bonus.  

I say no, but who knows maybe one day someone with a bunch of elite divisions will destroy my armies.  

With specialization, you can make crafted items faster than their normal counterparts.  Doesn't make crafted items awesome but if you pick just one type of crafted item to make per city and specialize one buildings you can crank them out very quickly.  If you build a second building it's even faster and if you specialize the second building it's faster still (although you loose all you flexibility for that city if you specialize the second crafting building).

When you have reached your maximum maintenance budget on an army, and want to make it stronger without incurring more maintenance cost, then adding equipment will do that for you. But I imagine you'll have spent a few months building that army up, and many cities' worth of output to obtain the equipment.

The "double bonus" only applies to elite divisions, which are limited in size. For spears the limit is 200 (100 for bows, 150 for swords, 60 for cavalry). Also each elite division must have its own commander of the same unit type. So one army could have five elite divisions of spears for a max of 1000 with double bonus, but each division would also need a spear commander. Do that in 10 cities and you have a total of 2000 elite spearmen for your entire account; not much of a threat to anyone.

The elite divisions are useful for small, single-division armies (which I use to occupy resource squares). They're basically useless for a large army with one commander; in that case you'd probably want all troops in one division so they can all take advantage of the commander's bonuses.